Go to Control Panel

Both "On battery" and "Plugged in" should be 100%

if you are using power saving mode plan then your CPU clock speed will be reduced i.e turbo boost will not work so change your plan settings to high performance mode

There has been a huge thermal throttling issue with these laptops when they hit 62-70c.

Turbo Boost is marketing.  The CPU will do that ON ONE CORE only when its basically doing nothing else.

The POWER GADGET will show you how little this happens.

https://software.intel.com/en-us/articles/intel-power-gadget-20

yeah I know that happens on only one core but even when I'm playing heavy games or stress testing the cpu it never kicks in. I don't know what to do :/
But is turbo boost that significant while playing games? If not then I can stay without it :/

Yeah everything is set to 100% but still turbo boost never kicks in :/
even in high performance profile

I know this is an old question, but I would like to leave here the solution that worked for me. I am using a Dell Inspiron 7577, also with an i7-7700HQ. I first tried updating the BIOS and the Chipset device driver to the latest version, but that had no effect.

I changed the laptop's power plan (Control Panel > System and Security > Power Options) to Balanced and it started turboing again. The previously selected power plan was named Dell.